Rivet setter



2 Sheets-Sheet 1 RIVET SETTER W. M. HANNEMAN May 8, 1962 Filed July 10, 1957 United States Patent Ofifice 3,033,410 Patented May 8, 1962 3,033,410 RIVET SETTER Walter M. Hannernan, Wheaten, 111., assignor to Hlinois Tool Works, Chicago, Ill., a corporation of Illinois Filed July 10, 1957, Ser. No. 671,025 3 Claims. (Cl. 218-42) This invention is concerned with an apparatus or device for setting rivets, particularly blind rivets.

As is well known, blind fasteners or blind rivets are commonly used when only one side of a workpiece is readily accessible. Such rivets or fasteners generally include a part which is inserted through a hole and then expanded on the backside of a workpanel or the like. Many such blind rivets or fasteners require a considerable pulling force for properly setting them in position. This invention is concerned with an apparatus or device for applying such a pulling force for setting blind rivets.

This invention is concerned generally with a rivet-setting apparatus or device which requires an absolute minimum of skill on the part of the operator.

It is an object of this invention to provide a rivetsetting device or apparatus which is automatically turned ofi at the completion of a rivet-setting operation, and wherein the parts automatically return to proper position for the inception of another rivet-setting operation.

It is a further object of this invention to provide a machine for setting blind rivets which utilizes, as a source of power, a small universal-type electric motor readily available in commerce.

Other and further objects and advantages of the pres- I at 40 and depressed by a flexible member 42 accessible cut invention will be apparent from the following descrip- I tion when taken in connection with the accompanying drawings wherein:

FIG. 1 is a front view of a rivet-setting machine constructed in accordance with the principles of this invention;

FIG. 2 is a side sectional view as taken substantially along the line 2-2 of FIG. 1;

FIG. 3 is an enlarged detail view of a portion of FIG. 2;

FIG. 4 is a horizontal sectional view as taken along the line 4-4 of FIG. 2;

FIG. 5 is an enlarged detail sectional view as taken along the line 5--S in FIG. 4;

FIG. 6 is an enlarged sectional view as taken along the line 6-6 in FIG. 4;

FIG. 7 is a side view of an installed rivet, the workpiece being shown in cross section;

'FIG. 8 is a perspective view of the installed rivet; and

FIG. 9 is a fragmentary view similar to a part of FIG. 6 and showing a modification.

Referring now in greater particularity to the drawings, and first to FIGS. 1 and 2, there will be seen a rivet-setting machine 1!) constructed in accordance with the principles of this invention. This machine includes a housing, generally designated by the numeral 12, supporting a universal-type electric motor 14 and gear-reducing unit 16. The gear-reducing unit 16 has an output shaft 1'8 on which there is fixed a pinion 20.

The housing rotatably mounts a large gear 22 (see also FIG. 4) meshing with the pinion and having. an eccentric hub or cam 24 extending upwardly therefrom. The eccentric hub or cam 24 forms a crank rotating within a sleeve 26 having a connecting rod 28 formed integral therewith. The end of the connecting rod 28 is pivotally connected at 30 to a clevis 32 having a threaded stud 34 thereon.

The rivet setter 10 is provided with the usual flexible electric cord 36 and this is connected through a switch 38 to motor 14 (the latter connections not being shown). The switch has an operating button (FIG. 3) indicated from the rear of the rivet setter. Depression of the operating button 40 causes a projection thereof at 44 to shift a plunger 46 reciprocably mounted in a slide member 48. The plunger 46 remains shifted (to the left as viewed in FIG. 2), by virtue of an over center spring (not shown) in switch 38 until engaged by lever 52 for return movement as shall later be explained. The end of the plunger 46 bears against one end 50 of a crescent-shaped lever 52 pivoted at 54 in the machine housing. The lever 52 par tially encircles the pinion 20 and associated parts, and the opposite end thereof is positioned at 56 below the large gear 22. A pin 58 (FIG. 2) depends from one of the spokes 60 of the gear 22, and is positioned to engage the end 56 of the crescent-shaped lever when the lever has been rocked in a clockwise direction by the plunger 46. As will be understood, the gear 22 rotates in a clockwise direction, in accordance with which the depending pin 58 engages the crescent-shaped lever with a wiping action, whereby to pivot the crescent-shaped lever in a counterclockwise direction to return the plunger 46 to its initial position, and thereby to open the switch 38.

The gear is provided with a thickened rim portion 62 (FIGS. 4 and 5) extending through substantially 180 of arc. A fiber brake 64 is mounted within the housing 12 adjacent the periphery of the gear 22, and is provided with upper and lower plates 66 and 68, respectively. These plates may be of fiber or other suitable brake material, and preferably are separated by a section 69 of rubber or similar material to facilitate adjustment of the plates. The plates 66 and 68 are engageable with the thickened rim portion 62 of the gear 22, and are respectively adjustable by means of setscrews 70 and .72 threaded through the housing and having locknuts 74 and 76 threaded thereon. The pin 58 is designed to open the switch 38 at a particular time (and, in this connection, it will be noted in FIG. 4 that the particular spoke 60 on which the pin is mounted is of rather considerable arcuate extent and is provided. with a series of apertures 78, any one of which may re-,

ceive the pin 58 for adjusting the timing) and inertia of the motor and gearing continues the parts in motion, but the parts are stopped in a particular position by friction of the brake 64. In order to insure stopping of the gear substantially in the position intended, a second brake 79 similar to the brake 64 preferably is provided and is spaced somewhat less than 90 behind the brake 64.

The housing 12 is provided with a boss or protuberance 80 having a sleeve bearing 82 therein. 32 to which the connecting rod 28 is pivoted slides in this hearing. A reducing fitting 84 has the externally threaded larger end 86 thereof threaded into the protuberance 80, and a jam nut 88 locks the fitting in place. A tube 90 is threaded onto the smaller end 92 of the fitting, and a jam nut 94 securely locks the tubing in place.

The threaded end 34 of the clevis 32 is threaded into a rod 96 which is longitudinally reciprocable in the fitting 84 and in the tube 90. The rod is provided at its outer end with a reduced section Q8 providing a shoulder 100. An axial bore 102 extends into the outer end of the rod and is deflected laterally out through the side of the rod, as at 104. A retractor tube 166 is threaded onto the rod 96 at 168 at a position displaced from the end of the reduced section 92 of the fitting 84. The retractor tube is recip rocal within the tube 90 which, for purposes of distinction, will hereinafter be referred to as a thrust tube. The outer end of the retractor tube has a bore which is in part tapered inwardly, 'as at 110, to urge together the The clevis is seated against the shoulders 116 and 100. The inner surfaces of the collet fingers are serrated as at 120 for gripping a fastener, as will be set forth hereinafter. Furthermore, the retractor tube is provided with a lateral aperture 122 aligned with the side opening 104 of the rod 96, and the thrust tube 90 is provided with a similar lateral aperture 124.

A thrust plate or button 126 closes the outer end of the thrust tube and is secured thereto in any satisfactory manner such as having a reduced portion forming a press fit within the thrust tube. The thrust plate 126 is provided with a tubulation 128 extending internally of the thrust tube and of the retractor tube to provide stability for the shank of a fastener.

The blind fastener or rivet with which the rivet setter heretofore shown and described is to be used is shown in FIG. 6 in association with the rivet setter, and it is identified by the numeral 130. The rivet includes an aluminum tube 132 having an enlarged head 134 at one end thereof, a circumferential flange 136 being interposed between the head and tube. The rivet also includes a shank 138 having rings or serrations 140 thereon which are gripped by the serrations of the collet fingers at 126. The opposite end of the shank is provided with a slightly enlarged head 142 having scalloped cutting points 144. When the shank is pulled to advance the head 142 toward the head 134, the scalloped cutting points shear the tube or sleeve 132 outwardly into petals 146, as shown in FIGS. 7 and 8. The petals 146 flare radially outward on the backside of a workpanel 148 to which a workpiece 159 is thus secured. The shank 138 is provided with a reduced section at 152, and the shank hence breaks off after the head 142 has been pulled in as far as it will go to clamp the workpiece 150 against the workpanel 148.

Operation The serrated shank 140 of one of the rivets 130 is inserted through the thrust plate 126 of the rivet setter, and is gripped lightly by the serrations ofthe collet fingers at 126 due to the action of the spring 118. The tube or sleeve 132 and head 142 of the rivet then are inserted through a workpiece and a workpanel, and the pushbutton 40 is actuated by momentary manual depression thereof. This causes movement of plunger 46 to an over-center position which in turn pivots the crescent-shaped lever 52 in a clockwise direction and simultaneously starts the motor in a counterclockwise direction as viewed in FIG. 4. This causes clockwise rotation of the large gear 22 which acts through the hub or crank 24 to pull the connecting rod 28.

This acts through the clevis 32 and the rod 96 to pull the retractor tube 106. This causes the cam surface 110 of the retractor tube to clamp the collet fingers 120 tightly in against the serrated shank 140 of the rivet while the shank is pulled from the rivet, causing the head 142 to shear the tube 132 into the petals 146, as previously indicated. As also has been indicated, the shank 138 of the rivet breaks off when fully withdrawn.

Immediately after this breaking of the rivet, the depending pin 58 on the large gear 22 engages the end 56 of the crescent-shaped lever 52, thus moving the plunger 46 in a reverse direction and opening the switch 33. The motor thus is deenergized but the parts continue to move by virtrue of their inertia. However, the thickened rim portion 62 of the large gear 22 now engages the brake 64, and, as a result, the parts coast to a braked stop substantially in the position shown in the drawings. The second brake 79 engages the thickened portion 62 of the large gear just after the pin 58 has tripped the lever 52. As the connecting rod approaches the fully extended position of FIG. 4, the eccentric reaches a dead center position, after which the connecting rod is reversed in its movement by the gear and the eccentric. This reversal, with proper adjustment of the brakes, tends to bring all of the moving parts to a stop adjacent the dead center position. The

mechanical arrangement is such that the gear 22 can stop within a few degrees of the dead center position in either direction without appreciably affecting the position of the collet fingers. Thus, it will be seen that the motor control means and brake means are arranged for starting and stopping the operation of the large gear in a cyclic pattern from a starting position, substantially as shown in FIG. 4, through substantially 360 of revolution. The control means intermittently renders the motor ineffective to drive the large gear after rotation thereof through substantially 180 from the starting position and the brake means is operable substantially at the beginning of the second 180 of rotation of the large gear to frictionally retard and stop the same substantially at the starting position. The parts thus are in a position to pick up another rivet, and insertion of this rivet forces the broken off shank rearwardly through the bore 102 and out through the lateral openings 194, 122, and 124.

Modification Under some conditions, it has been found that a brokenofi shank 138 occasionally may not be properly ejected from the above described mechanism. When a broken ofi shank is trapped and retained without ejection, then forward movement of rod 96 upon the next cycle of the rivet setter places considerable strain on the rivet setter tending to cause damage to internal parts or to displace the thrust plate or button 126. Stated another way, sometimes a broken shank may become trapped internally instead of ejecting rearwardly and the collet, as it moves forwardly on the next cycle, may engage the trapped piece and cause great pressure on the parts. To guard against damage to parts under such a situation, the gripping end of the previously described form of the invention may be modified as shown in FIG. 9, similar parts being identified by similar numerals with the addition of the sufiix a.

The thrust plate of button 126a is formed as a hollow cap having internal annular grooves 154. Each such groove has a rather steep trailing edge 156 and the rear groove has a tapered forward edge 158 facilitating mounting over other parts to be described. The forward groove referably has an abrupt forward edge. The cap-like thrust button 126a fits over the end of the thrust tube a, and an annular groove 160 is formed in the outer surface of the tube near the front or outer end thereof. A plastic or similar elastic, deformable O-ring 162 is received in the groove 16% and in the forward groove 154 to hold the cap-like thrust button in place. The spring 118a preferably is seated on a flanged ferrule or bushing 114a, rather than an integral extension of the collet 112, and the retraction tube 166:: conveniently is threaded at 1128a on to the front end of the pull rod (as 96, in FIG. 6).

Any force such as from a trapped broken shank as abovementioned tending to displace the thrust button by forward movement of rod 96 is yieldingly resisted by the O-ring 162. When a certain limit is reached, the button slips over the ring, and the ring is received in the second groove 15d. It will be appreciated that the forward groove 154 normally receives the O-ring 162 to secure the thrust button on the rivet setting device. The thrust button may then be partially dislocated so as to be secured in the second groove. Sutficient force eventually could force the thrust button entirely from the rivet setter without damage.

It will be understood that the specific embodiments of the invention as herein shown and described are for illustrative purposes only. Various changes in structure will no doubt occur to those skilled in the art, and are to be understood as forming a part of the invention in so far as they fall within the spirit and scope of the appended claims.

I claim:

1. A machine for setting rivets of the type requiring a pulling force thereon, said machine comprising means for releasably gripping such a rivet, a tractive member secured to said gripping means for pulling thereon, a relatively large gear, means interconnecting said gear and said tractive member for pulling thereon, a relatively small gear meshing with said l-arge gear to form therewith a reducing gear set, a rotary motor, a source of power for rotating the motor to drive said gears to pull, through said tractive member, said gripping means, and control means for starting the operation of said large gear in a cyclic pattern of substantially 360 of revolution from a predetermined starting position, said control means including a device internittently operable to connect the source of power and render the motor effective to start the drive of said large gear from the starting position, a member carried by said large gear for actuating said device to disconnect the source of power and render the motor ineffective to drive the large gear after substantially 180 of rotation of the large gear, and brake means operable substantially at the beginning of the second 180 of rotation of the large gear to frictionally retard rotation thereof and stop the same substantially at its starting position.

2. A machine as claimed in claim 1, wherein the intermittently operable device includes a pivoted lever having the inner end thereof positioned adjacent the periphery of the large gear and extending substantially in the direction of rotation thereof for wiping actuation of the lever by the member carried by the large gear.

3. A machine as claimed in claim 1, wherein the brake means includes a peripheral enlargement at the side of the large gear extending throughout substantially half the periphery thereof and with the major portion of the enlargement located in the second of revolution when the large gear is in its starting position, and wherein friction means engages the leading end of said enlargement substantially upon disconnection of the source of power for retarding rotation of the large gear and stopping the same substantially at its starting position.

References Cited in the file of this patent UNITED STATES PATENTS 1,209,381 Bates Dec. 19, 1916 1,666,275 Walsh Apr. 17, 1928 1,943,139 Myers Jan. 9, 1934 2,075,162 Begg Mar. 30, 1937 2,170,323 Gorshkofi Aug. 22, 1939 2,384,434 Bettington Sept. 11, 1945 2,406,949 Huck Sept. 3, 1946 2,465,403 Smith Mar. 29, 1949 2,571,303 Spiller Oct. 16, 1951 2,595,551 Springate May 6, 1952 2,794,567 Stau June 4, 1957 2,965,258 Wilson et a1 Dec. 20, 1960 3,010,597 Beasley et al Nov. 28, 1961 

